title: Disparities of conjugating protective enzyme activities in the colon of patients with adenomas and carcinomas.
abstract: OBJECTIVE
  To investigate the metabolic enzymatic capacity of the colon mucosa to detoxify noxious carcinogenic compounds.
  
  
  METHODS
  We investigated the activity of 2 conjugating enzymes-the microsomal uridine glucuronosyltransferase (UGT) and the cytosomal glutathione S-transferase (GST) in the uninvolved mucosa of the colon transversum and sigmoideum in patients with adenomatous polyps and colorectal cancer. Biopsies were taken from the mucosa during colonoscopies which were done for clinical (diagnostic) reasons. After storage, the biopsy material was homogenized and after differential centrifugation the enzyme assays were performed with 4-nitrophenol (UGT) and 1-chloro 2,4-dinitrobenzene (GST) as substrates.
  
  
  RESULTS
  About 48 patients were included of which 28 had adenomas and 20 had colorectal carcinomas confirmed by histopathology. Enzyme activities were expressed as nmol/mg per minute protein for the GST and as pmol/mg per minute protein for the UGT. Analysis of variance (F-test) indicated that both enzymes were more widely distributed in adenoma than in cancer patients. The means ± SD were smaller for cancer patients: GST for adenomas 268 ± 152 vs 241 ± 69 for carcinomas and UGT for adenomas 197 ± 200 vs 150 ± 86 for carcinomas.
  
  
  CONCLUSIONS
  Compared to patients with adenomatous colon polyps those with colorectal carcinoma exhibited a lower capacity of detoxifying enzyme metabolism and their activities clustered over a smaller range.
authors.affiliation: Harald P Hoensch, Internal Medicine, Marien Hospital, D-64285 Darmstadt, Germany.
authors.forename: Harald P
authors.initials: HP
authors.lastname: Hoensch
authors.forename: Hennie M J
authors.initials: HM
authors.lastname: Roelofs
authors.forename: Lutz
authors.initials: L
authors.lastname: Edler
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Kirch
authors.forename: Wilbert H M
authors.initials: WH
authors.lastname: Peters
mesh_terms: D000236:Adenoma / Q000201:enzymology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001706:Biopsy; D002277:Carcinoma / Q000201:enzymology* / Q000473:pathology; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology; D004137:Dinitrochlorobenzene / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D014453:Glucuronosyltransferase / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D008658:Inactivation, Metabolic; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009596:Nitrophenols / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D014408:Biomarkers, Tumor; D004137:Dinitrochlorobenzene; D009596:Nitrophenols; D014453:Glucuronosyltransferase; D005982:Glutathione Transferase; C024836:4-nitrophenol
keywords: Colon adenoma; Colon carcinoma; Detoxification; Glutathione S-transferase; UDP-glucuronosyltransferase